FORD ESCAPE MECHANIC PROBLEM

2005 Ford Escape • 137,500 miles

After driving for about an hour on the highway the car just died. I still had lights, radio, etc and the engine was trying to turn over but eventually had to be towed. After sitting for 2 days it started right up. We took it to a mechanic who said it wouldn't code so he didn't know what was wrong with it. So now it sits in the driveway not being driven because I'm afraid to have it die in traffic. Any suggestions? Short of just replacing things randomly should I take it to a mechanic who could check things manually. I'm a female and I can't work on this myself.